Do Bridges Leak? Natural Gas Sure Does – Just Ask California…

By Andrea Lang, Energy Fellow

Last week, I wrote about why Oregonians should be wary of shifting away from coal by investing in more natural gas infrastructure to power our electric grid. Besides the fact that such infrastructure would be in place for years and thus is unlikely to be a “bridge” to renewable energy, it is not necessarily less carbon intensive than other fossil fuels.  While burning natural gas results in less CO2 emissions than coal, there are also lots of methane leakages during natural gas production, storage, and transportation. And since methane is 25-37 times more potent (it depends on the timeframe considered) as a greenhouse gas than CO₂, these leakages are significant.  The ongoing methane leak in California, along with numerous other leaks across the country, illustrates the hidden climate cost of natural gas.

A methane leak in Porter Ranch, California has already leaked more than 86,000 metric tons of methane, or the equivalent of more than seven million metric tons of CO₂. That leak is expected to continue at least into late February or March. In the meantime, you can watch the methane emissions go up in real time on a methane counter created by the Environmental Defense Fund. The leak has caused California’s governor to declare a state of emergency in the area, and has resulted in thousands of evacuations. But in addition to the local impacts of the leak, it highlights one of the major problems with natural gas in terms of global climate impacts. Though invisible to the eye, the leak in California is currently the daily equivalent of driving seven million cars.

  

The California methane leak is by no means an isolated incident. A recent study concluded that for natural gas to produce more climate-friendly electricity than coal, leakage must be kept below 3.2%. However, there is a lot of uncertainty about how much leakage is actually occurring from natural gas infrastructure and whether it is in fact below that 3.2% threshold. Although the EPA has estimated that leakage rates are well under the threshold, numerous studies (see here, here, and here) have concluded that EPA may be drastically underestimating methane leakage.

Chances are, even with all of these leaked emissions, natural gas is still cleaner than coal. But the scary part (aside from the terrible local impacts of large-scale leakages like the one in California) is that nobody is totally sure about how much fugitive emissions really occur. And with natural gas being touted as the “bridge” to a renewable and sustainable energy future, it seems like a big risk to take. In the transition away from coal, we would be much better served by investing in truly green infrastructure, increasing the percent of electricity from solar, wind, and other renewable energy sources.